Belt-driven bicycle
3 with kevlar belt drive]] District]] rear hub on a Trek District]] rear hub on a Trek Soho]] A belt-driven bicycle is a chainless bicycle that uses a toothed rubber synchronous belt to transmit power from the pedals to the wheel. The belts are typically made by the same manufacturing companies that produce timing belts for automobiles, machineries, and other synchronous belt drive applications. The application of belt drives to bicycles is growing, especially in the commuter bicycle market, due to the low maintenance and lubrication-free benefits. Benefits * Belts do not rust. ** Lubrication is not required. ** Cleanliness due to lack of lubrication. ** Little to no maintenance. * Smoother operation. A belt's teeth completely engage into the system for decreased friction and increased pedalling efficiency. * Longer life than bicycle chains. * More resistant to debris than chain drives. * Quieter than chain. * Some belt systems are more lightweight than conventional chains. Disadvantages * Scarcer at shops than bicycles with conventional chain. * Belt-driven bicycles often incorporate proprietary plastic gears, which wear out more quickly than metal. Specially designed lightweight metal sprockets are available on some models and in kits. * Derailleurs can't be used, so an internal-gear hub is used if gears are required. * The belt cannot be taken apart, as a chain can, so a frame must be able to accommodate the belt by having an opening in the rear triangle or an elevated chain stay. * Belts come in limited length selection. History In 1984 and 1985, Mark Sanders, a designer who had earned his degree in Mechanical Engineering from Imperial College, London, designed a folding bicycle as part of his graduate studies in an Industrial Design Engineering (IDE) program. The program was run jointly by Imperial College and the Royal College of Art in London. He collaborated with a design engineer from Gates Corporation to outfit his bicycle with a belt, rather than a chain. When his project was complete, Sanders chose entrepreneur and former Greg Norman manager James Marshall and a Glasgow manufacturer to turn his award-winning design into a product. The manufacturer coined the name STRiDA, and in 1987 the bicycle began rolling off the production line. In 2002 production was moved to Taiwanese manufacturer Ming Cycle in order to meet increased demand, and as of 2007, Ming Cycle fully owned the STRiDA brand and intellectual property rights. iXi bicycles, distributed in the United States by Delta Cycle Corporation, followed in 2004 with a compact design that, like STRiDA, featured a grease-free belt drive. Possibilities for belt-driven bicycles have widened as hub gears inside the rear hub, were applied. In lieu of a derailleur, the hub gear allows riders of belt-driven bicycles to shift easily. Major internal hub makers include Shimano (Nexus), SRAM and Rohloff. In 2007, Gates Corporation developed a high-modulus synchronous belt and sprocket system called the Carbon Drive System. The belt’s pitch allowed for lower tension requirements to help prevent skipping. Lightweight, patent-pending sprockets have Mud Ports, openings under each tooth, which work to slough off debris. Early adopters who helped evaluate, revise and introduce this system included Frank Scurlock of Spot Brand Bicycles and Kalle Nicolai of Nicolai Ltd. Early in the 21st century an increasing number of bicycle companies, including Trek, offer belt-driven bicycles. See also * Chainless bicycle References External links *Abio Bikes belt drive *Strida *iXi *CDRIVE belt system *Carbon Drive Systems *Delta's Hybrid Belt Drive Bike *Gates Belts *Rain City Choppers Red Line *SPOT Brand 2008 belt drive bikes *Trek Bikes *Falk Bikes City Bike *Falk Bikes Road Bike Category:Cycle types ja:ベルトドライブ (自転車)